Honda TRX300 Piston Kit - Wiseco - 10.251 CR, 74.50 mm Bore, 10.25:1 CR - `88-`00. This Wiseco piston kit replaces the stock piston with a forged, application-specific piston for Honda TRX300 models from 1988–2000, designed to meet tight tolerances for strength and durability.

Wiseco forged 4-stroke pistons are engineered for specific powersports engines and machined to precise dimensions in Mentor, OH. This kit is a +0.5 mm oversize (74.50 mm bore) with a 10.25:1 compression ratio (10.251 CR) and is compatible with both 2WD and 4WD TRX300 variants. The construction uses dedicated forgings to optimize the strength-to-weight ratio, and the kit includes the necessary piston rings, wrist pin(s), and circlips for a complete, correct fitment.

Features

• Fitment: Honda TRX300 (1988–2000), 2WD/4WD, +0.5 mm (74.50 mm bore)
• Compression Ratio: 10.25:1 (10.251 CR)
• Forged 4-stroke piston engineered for specific engine applications
• Includes piston rings, wrist pin(s), and circlips
• Forged, machined, and inspected in Mentor, Ohio, USA

This Wiseco kit is intended for riders and builders who want a reliable, OEM-replacement-level forged piston with the benefits of improved material tensile strength and application-specific machining. It’s suitable for routine rebuilds or moderate performance builds where correct sizing and durability are priorities.

If you have questions or want help confirming fitment, call us directly — 512-982-9393 (TX) or 562-981-6800 (CA). We have two locations offering installation and customization services: Austin, Texas and the Los Angeles, California area. If you are considering purchasing multiple items, contact us for shipping discounts. We install on premises at both locations.

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov